X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/0fee61eb2ff1807c5f32a34499ef2753b6fcd9a5..e275090f9f712a8d9dda4e309ce38bb520778016:/symm/cbc-def.h

diff --git a/symm/cbc-def.h b/symm/cbc-def.h
index 59c76f8a..480f5796 100644
--- a/symm/cbc-def.h
+++ b/symm/cbc-def.h
@@ -155,7 +155,7 @@ void pre##_cbcencrypt(pre##_cbcctx *ctx,				\
 {									\
   const octet *s = src;							\
   octet *d = dest;							\
-  octet b[PRE##_BLKSZ];							\
+  octet b[PRE##_BLKSZ], bb[PRE##_BLKSZ];				\
   octet y;								\
   unsigned i;								\
 									\
@@ -173,7 +173,8 @@ void pre##_cbcencrypt(pre##_cbcctx *ctx,				\
   if (sz < PRE##_BLKSZ) {						\
     pre##_eblk(&ctx->ctx, ctx->a, ctx->a);				\
     BLKC_STORE(PRE, b, ctx->a);						\
-    if (d) { for (i = 0; i < sz; i++) d[i] = b[i] ^ (s ? s[i] : 0); }	\
+    if (!d) d = bb;							\
+    for (i = 0; i < sz; i++) d[i] = b[i] ^ (s ? s[i] : 0);		\
     memmove(b, b + sz, PRE##_BLKSZ - sz);				\
     memcpy(b + PRE##_BLKSZ - sz, d, sz);				\
     BLKC_LOAD(PRE, ctx->a, b);						\